This application proposes a retrospective cohort study to investigate health effects among former workers of a large chloralkali plant in Brunswick, Georgia. The plant operated from 1956 through 1994, resulting in considerable mercury exposure to both workers and the nearby environment. The current study will focus on the cohort of all workers employed for at least one year during that period. Mercury exposure in this cohort will be estimated by conventional means, and also by DMSA chelation challenge. The outcomes of interest will be broadly classified into three categories: neurological, renal, and reproductive. Neurological measurements will be obtained through a combination of physical examination and computerized tests. Renal outcomes will be determined in terms of several urinary proteins and enzymes, creatinine clearance and porphyrin profiles. A health questionnaire and subsequent medical record checks will generate data on the reproductive outcomes. Information on several medical, dental and dietary factors will also be collected in order to account for potential confounding effects. The study will contribute new information regarding the role of DMSA as a mercury chelating agent and the effect of mercury on porphyrin metabolism. It will also provide valuable replication of previous studies, by describing the relationship between mercury exposure and neurologic, renal and reproductive toxicity. Finally, this study will serve as a model of collaboration between a community, a local health department, a state health department, and a research university.